U.S. patent application number 17/253949 was filed with the patent office on 2021-10-14 for arrangement for transferring torsion torque, particularly in the form of a torsion spring or drive shaft made of composite fiber materials in order to achieve a high specific material usage.
The applicant listed for this patent is NEMOS GMBH. Invention is credited to Jan Peckolt, Jan Puetz, Roland Vilsmeier.
Application Number | 20210317890 17/253949 |
Document ID | / |
Family ID | 1000005737362 |
Filed Date | 2021-10-14 |
United States Patent
Application |
20210317890 |
Kind Code |
A1 |
Peckolt; Jan ; et
al. |
October 14, 2021 |
ARRANGEMENT FOR TRANSFERRING TORSION TORQUE, PARTICULARLY IN THE
FORM OF A TORSION SPRING OR DRIVE SHAFT MADE OF COMPOSITE FIBER
MATERIALS IN ORDER TO ACHIEVE A HIGH SPECIFIC MATERIAL USAGE
Abstract
The invention relates to a torsion carrier, particularly a
torsion spring, helical spring, drive shaft or balance shaft, which
enables significant material and installation space savings
compared to the prior art. The torsion carrier consists of a
plurality of, but at least two supporting layers lying radially one
above the other, each of which consists of at least one spiral coil
(1, 3), but preferably of a plurality of spiral coils made of
predominantly unidirectional composite fiber material, wherein at
least two of the supporting layers have a counterrotating spiral
coil orientation relative to one other. An elastic intermediate
spacer layer (2) is arranged between adjacent spiral coil layers,
by means of which a decoupling of the spiral coil expansions of
adjacent spiral coil layers is achieved. This achieves particularly
favorable, predominantly single-axis states of stress which allow
for a high level of material utilization.
Inventors: |
Peckolt; Jan; (Duisburg,
DE) ; Vilsmeier; Roland; (Duisburg, DE) ;
Puetz; Jan; (Duisburg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NEMOS GMBH |
Duisburg |
|
DE |
|
|
Family ID: |
1000005737362 |
Appl. No.: |
17/253949 |
Filed: |
June 18, 2019 |
PCT Filed: |
June 18, 2019 |
PCT NO: |
PCT/EP2019/066068 |
371 Date: |
December 18, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 5/145 20130101;
F16F 2224/0241 20130101; F16F 1/3665 20130101; F16C 1/02 20130101;
B32B 2250/03 20130101; B32B 2307/546 20130101; B32B 2597/00
20130101; F16F 2238/024 20130101; B32B 1/08 20130101; B32B 5/12
20130101; F16F 1/48 20130101 |
International
Class: |
F16F 1/48 20060101
F16F001/48; B32B 1/08 20060101 B32B001/08; B32B 5/12 20060101
B32B005/12; B32B 5/14 20060101 B32B005/14; F16F 1/366 20060101
F16F001/366; F16C 1/02 20060101 F16C001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 18, 2018 |
DE |
10 2018 114 583.7 |
Apr 16, 2019 |
DE |
20 2019 102 181.0 |
Claims
1. A torsion carrier having at least two layers consisting in each
case of at least one spiral coil made of composite fiber material,
wherein the at least two layers have a mutually opposed spiral coil
direction of rotation and at least one spacing elastic intermediate
layer arranged between aid the at least two layers.
2. The torsion carrier as claimed in claim 1, wherein main fiber
directions of the spiral coils are at least approximately oriented
in a main direction of extent of the spiral coils.
3. The torsion carrier as claimed in claim 1, wherein at least one
layer of the at least two layers contains a plurality of spiral
coils.
4. The torsion carrier as claimed in claim 1, wherein gaps are at
least partially provided between adjacent spiral coils of a layer
of the at least two layers, and/or a filling of elastic filling
material is at least partially arranged between adjacent spiral
coils of a layer of the at least two layers, and/or the at least
one spacing elastic intermediate layer at least partially extends
into a region between adjacent spiral coils of a layer of the at
least two layers.
5. The torsion carrier as claimed in claim 1, wherein the at least
one spacing elastic intermediate layer and/or fillings between
spiral coils of a layer of the at least two layers contain cavities
and/or incisions and/or holes and/or are at least partially formed
from a foamed material and/or from a damping material.
6. The torsion carrier as claimed in claim 1, wherein at least a
portion of the spiral coils, on a surface oriented toward the at
least one spacing elastic intermediate layer, has tension-relieving
fibers with an orientation transversely with respect to a main
direction of extent of the spiral coils.
7. The torsion carrier as claimed in claim 1, wherein ends of the
torsion carrier have an inside and/or outside diameter increasing
in a funnel-shaped manner, and/or the spiral coils have a changed
pitch in a region of the ends of the torsion carrier.
8. The torsion carrier as claimed in claim 1, wherein the spiral
coils each have an increased layer thickness in a region of their
ends, and/or end pieces are attached to the ends of the spiral
coils.
9. The torsion carrier as claimed in claim 1, wherein the spiral
coils each have a reduced width in a region of their ends and said
spiral coils thus have an increased deformation capability in an
event of bending in a circumferential plane.
10. The torsion carrier as claimed in claim 1, wherein the at least
two layers include more than two layers of spiral coils decoupled
from one another by elastic intermediate layers.
11. The torsion carrier as claimed in claim 1, wherein the at least
two layers include layers having at least three different spiral
coil orientations spaced by elastic intermediate layers.
12. The torsion carrier as claimed in claim 1, wherein a core
increasing the flexural rigidity or transverse force load-bearing
capability is arranged radially on an inside of the at least two
layers of spiral coils.
13. The torsion carrier as claimed in claim 1, wherein a changing
inside and/or outside diameter is formed in a direction of ends of
said torsion carrier.
14. The torsion carrier as claimed in claim 1, wherein a tube
consisting of the at least two layers of spiral coils or a round
bar consisting of the at least two layers of spiral coils has an
external form of a screw.
15. A torsion tube spring, torsion bar, flexurally elastic torsion
shaft, drive shaft or helical spring consisting of the torsion
carrier as claimed in claim 1.
Description
PROBLEM
[0001] Torsion-loaded tubes and similar torque-carrying components
undergo multi-axial states of stress. The shear stress in an
imaginary vertical section through a torsion-loaded tube is
converted in accordance with Mohr's circle into two orthogonal main
stresses in the directions of +/-45.degree., per direction under
tensile and compressive stress. This state of stress is not a
problem for amorphous materials (metals) in terms of their material
limits. However, composite fiber materials are particularly
sensitive to multi-axial states of stress. In order to carry the
main stresses, the laminate layers are preferably laid in the main
directions of stress. Classic torsion tubes made of composite fiber
materials are therefore constructed from fibers of differing
directions of rotation. For example, fibers with a winding
direction of +45 degrees carry the tensile stresses and fibers with
a winding direction of -45 degrees carry the compressive stresses.
The fibers of both directions lie orthogonally with respect to one
another here. However, laminate layers not lying parallel to one
another may experience unfavorable interactions:
[0002] A tensile or compressive loading in a fiber direction leads
to a positive or negative longitudinal extension. When directly
attached in a continuous laminate structure, this leads to a
transverse extension in the other fiber direction in each case.
However, composite fiber materials have only a small extensibility
transversely with respect to the fiber direction. There are
predominantly two reasons for this: the fibers lie at close
distances from one another and have a substantially higher degree
of rigidity than the surrounding matrix material, as a result of
which only a small extension distance is available, and therefore,
even in the event of small transverse extensions of the composite,
the matrix material overstretches (predominantly relevant in the
case of composite materials with amorphous fibers, for example
glass fibers), or the fibers themselves because of their
anisotropic composition have such a sensitive nature that they are
damaged even in the event of small transverse loads (this is
relevant for example in the case of carbon fibers).
[0003] Even in the event of small transverse extensions,
interlaminar cracks are therefore formed, as a result of which the
longitudinal load-bearing capability of the composite damaged in
this manner is reduced and the component may fail.
Compression-loaded regions of the laminate are particularly
affected because of their reduced stability.
[0004] Repeated load changes lead here to an accelerated
propagation of cracks, and therefore, inter alia, high fatigue
allowances in the dimensioning are required in order to generally
lower the level of extension. This means that a component with a
high number of anticipated load cycles has to be realized with
significantly more use of material in order to limit the extensions
and stresses. This has a greatly negative effect particularly in
the case of spring components (torsion springs here) since the
elastic energy which can be stored is proportional to the product
of stress and extension. Alternatively, because of the linear
interrelationship of the two sizes, the energy which can be stored
is proportional to the square of the stress or to the square of the
extension.
[0005] The generally unfavorable material utilization is thus a
substantial reason for the previously low prevalence of composite
fiber materials in such applications.
[0006] A further problem is the failure of composite fiber torsion
components due to shear loads. An insufficient deformation
capability leads here to interlaminar formation of cracks between
parallel fiber strands.
SOLUTION APPROACH
[0007] While torsion carriers having conventional laminate
structures withstand only relatively small stress levels because of
the abovementioned sensitivity in relation to multi-axial states of
stress (a fiber-parallel stress of up to approximately 300 MPa in
the case of GFRP), with the solution approach described below
significantly higher stresses (up to approximately 600 MPa in the
case of GFRP) have been able to be achieved. The doubling of the
stress level has the result that it is possible to realize [0008]
torsion-transferring components with approximately half the use of
material [0009] torsion springs with approximately 1/4 of the use
of material because of an extension approximately parallel to the
stress.
[0010] In addition to advantages in terms of weight and costs, the
proposed concept can also permit considerable savings in respect of
the required construction space.
[0011] A structure is proposed having separate layers of individual
spiral coils which have an opposed (winding) direction of rotation
of the fibers. Spiral coils are understood as meaning helical
strips of limited width that are coiled around the longitudinal
axis of the component helically at a certain pitch angle on a
cylindrical circumferential surface. The opposed coils are mutually
supported radially under loading, wherein the torsion loading is
converted into tensile load(s) in the outer spiral coil(s) (1) and
compressive load(s) in the inner spiral coil(s) (3). The spiral
coils of a (radial) layer plane are intended to be able to change
their distance with respect to one another according to the form of
loading, as a result of which an extension transversely with
respect to the longitudinal direction of the spiral coils is made
possible. In addition, the compensating gap which is provided
assists shear deformations between the adjacent parallel spiral
coils of a layer.
[0012] The proposed structure means that the spiral coils are
intended to undergo uniaxial states of stress as far as possible,
with predominantly tensile or compressive loads in the longitudinal
direction, as a result of which said spiral coils can be
constructed predominantly from unidirectional laminates (fibers in
the longitudinal direction of the spiral coils) or by means of
slightly twisted composite fiber material (with a mean fiber
orientation in the longitudinal direction of the spiral coils). In
an advantageous embodiment, the fibers deviate from the
longitudinal direction of the spiral coils by below 10 degrees,
furthermore preferably by below 5 degrees.
[0013] So that the longitudinal extension of the spiral coils of a
layer is not directly impressed onto the spiral coils of an
adjacent layer lying transversely with respect thereto and instead
the compensation of the transverse extension takes place primarily
in the gaps provided for this purpose between the spiral coils, it
is advantageous if the layers are decoupled from one another by
means of a compensating zone which is called "intermediate layer"
below. The effect of the decoupling of the transverse extension is
illustrated by way of example in FIG. 9. An external spiral coil 1
extended by a tensile load is shown by way of example. An
intermediate layer 2a and an internal spiral coil 3 adjoin on the
inside. The intermediate layer 2a shown here by way of example in a
variant embodiment "a" undergoes an extension by connection to the
external spiral coil 1. The deformation capability of said
intermediate layer means that the extension is not impressed (or
only to a small extent) onto the compression-loaded internal spiral
coils 3. Instead of producing an interfering transverse extension
within the internal spiral coils 3, the extension leads only to an
increase in the size of the gap 5 between two adjacent internal
spiral coils 3, as a result of which the distance between the two
illustrated adjacent internal spiral coils 3 is increased (cf. FIG.
1).
[0014] The corresponding effect is also achieved in an analogous
manner for compressive loads in the internal spiral coils 3. In
this case, the intermediate layer 2 and the compensating gap 4 also
permit a shortening of the internal spiral coils due to compressive
loads to lead to a reduction in size of the gap (4) between the
external spiral coils 1 and thus to the external spiral coils 1
being protected against undesired transverse compressions.
[0015] The volume elements of the intermediate layer 2a, which
volume elements can be considered by way of example as cuboid
support elements between the intersecting spiral coils, because of
a simultaneous compression of the adjacent internal spiral coils 3
as a result of the compressive force (F Compression) and
lengthening of the external spiral coils 1 as a result of the
tensile force (F Tension) undergo a deformation to form a truncated
pyramid, see FIG. 10. This deformation capability ensures that the
longitudinal extension of the fibers of a layer is not transferred
to the composite fiber material of the spiral coils of the adjacent
layer, which may be referred to as decoupling of the transverse
extension.
Delimitation Over the Prior Art
[0016] Geometrically similar arrangements as in the present
invention can be found in the prior art particularly in the context
of flexible drive shafts. However, these inventions pursue a
different objective and accordingly differ in substantial device
features. For example, U.S. Pat. No. 8,984,698 describes metallic
spiral coils instead of composite fiber spiral coils. Or, in the
case of the arrangement which is known from US 2018/0258979 and
which likewise has great geometrical similarity, an elastic
intermediate layer is not provided. Since the latter has been able
to be established (simulatively) as an important element or a
prerequisite for the decoupling of composite fiber spiral coils and
the associated uniaxial states of stress, the described improvement
in the degree of material utilization has been demonstrated (in
experimental investigations).
Implementation Features
[0017] The coils of a layer plane can be designed in single or
multiple form. In multiple form means that a plurality of spiral
coils are contained per layer. In the case of a tubular component,
said spiral coils are wound parallel to one another at the same
pitch around the longitudinal axis of the tube, wherein the spiral
coils of a layer are at the same radial distance from the central
longitudinal axis of the tube. In a favorable embodiment, more than
three spiral coils, furthermore preferably more than six spiral
coils, furthermore preferably more than 10 spiral coils are used
per layer.
[0018] The angles of the spiral coils, i.e. the pitch of the
convolutions thereof, can be selected in accordance with the
requirements of an application and thus influence the rigidity of
the component. With respect to the longitudinal direction of the
component (tube), angles in the range of approximately 10 degrees
to 85 degrees or in the opposite layer of -85 degrees to -10
degrees are technically expedient. A favorable embodiment has
(direction of rotation) angles of approximately 45 degrees and -45
degrees for both winding directions. In order to produce
equilibriums of forces, a deviation can in each case be made from
said +/-45 degree arrangement by single-digit degree numbers, thus
resulting, for example, in arrangements with +40 degrees and -50
degrees.
[0019] Torsion elements which include a greater number of layers,
i.e. more than two layers, are also proposed, as a variant
embodiment of this invention. They can contain a plurality of
pairings of tension and compression layers which are each decoupled
by means of intermediate layers. By this means, the radial pressure
between the individual layers is reduced, and therefore softer
materials can be used and the entire component can be subjected
even to loads in the reverse direction of rotation of the torque.
When the direction of the torque is reversed, the previously
described external spiral coils are subjected to compressive loads
(instead of tensile loads as in the previously described basic form
of loading) and the internal spiral coils are subjected to tensile
loads (instead of compressive loads as in the previously described
basic form of loading). In this case, tensile loads (instead of
compressive loads as in the previously described basic form of
loading) occur between the layers and have to be transmitted via
the intermediate layer. In addition to the described variant with
two load-bearing layers (a tensile layer and a compressive layer),
variants having 3, 4, 5, 6 or a greater number of layers are also
advantageous.
[0020] It should be mentioned that, within the context of the
present invention, the term "internal spiral coils" relates to
spiral coils which are subjected to compressive forces when the
component is loaded in its preferred direction. By contrast, the
term external spiral coils relates to spiral coils which are
subjected to tensile loads when the component is loaded in its
preferred direction. In cases in which the described torsion
carriers are constructed in the radial direction from more than two
layers of spiral coils, the terms "on the inside" and "on the
outside" refer to the relative arrangement of a pairing of two
layers with respect to one another that are mutually supported in
the radial direction.
[0021] The result of the described construction for decoupling the
spiral coils of adjacent layers from one another and for decoupling
the spiral coils within a layer is that the stresses in the spiral
coils predominantly run in the fiber direction and interfering
transverse extensions are suppressed (or at least reduced). A high
utilization of the composite fiber material can thus be achieved,
and therefore higher deformation capabilities and stresses can be
permitted, as a result of which the components can be realized with
a smaller construction space and lower use of material than
conventional systems. With the given structure, a particularly high
specific extension energy can be stored in a torsion spring.
[0022] The invention provides a plurality of variant embodiments
for the intermediate layer (2):
[0023] The intermediate layer can be realized by an elastic
material, as a result of which it ensures spacing of adjacent
layers of opposed load-bearing spiral coils and its deformation
capability enables decoupling of the layers, as a result of which a
longitudinal extension of the spiral coils of one layer leads only
slightly to a transverse extension of the spiral coils of the
adjacent layer. In an advantageous embodiment, the intermediate
layer is connected to the load-bearing spiral coils, in particular
is connected in an integrally bonded manner. This can be of
fundamental importance since in particular the compression-loaded
spiral coils thereby undergo fixing and their free buckling length
(in respect of a failure of stability) is significantly
reduced.
[0024] For an integrally bonded attachment, use can be made of
special adhesion promoters permitting a particularly good
connection between composite fiber material and elastic
intermediate layer. Or an intermediate layer material can be used
which is connected particularly readily to the composite fiber
material, in particular an elastomer which cures or crosslinks
together with the synthetic resin of the composite fiber
material.
[0025] In order to obtain a high deformation capability to
compensate between load-bearing layers (or between the external
spiral coils (1) and the internal spiral coils (3)) and at the same
time to ensure a high load-bearing capability against radial
pressure between the layers or in order to limit energetic losses
(dissipative damping effects), use can be made of a relatively hard
material which obtains the required deformation capability simply
by appropriate shaping. In the context of the present invention,
this second variant of the intermediate layer (with a specially
shaped, relatively hard material) will also be referred to as
"elastic intermediate layer". For this purpose, FIGS. 4a to 4d
illustrate an arrangement, wherein the intermediate layer is
constructed in the form of individual rhombuses which are present
only in the regions in which spiral coils intersect. In regions in
which there is a gap (4 and 5) between the spiral coils in one of
the load-bearing layers, the intermediate layer is also
interrupted. The elastic intermediate layer here thus has gaps
which are designed as a radial continuation of the compensating
gaps between the spiral coils of a layer and either partially or
completely interrupt the intermediate layer.
[0026] In respect of the manufacturing, said shaping can be
produced prior to the connection of the two load-bearing layers, or
the material can be removed from the intermediate layer by material
abrasion through the gaps between the spiral coils (abrasion by
cutting or by laser abrasion or by cutting with a water jet), in
order to produce the surface interruptions. Alternatively, FIGS. 5a
to 5c present an arrangement in which the intermediate layer is
constructed from two layers (2b1) and (2b2). Said layers are each
arranged along the external spiral coil (1) and internal spiral
coil (3) and are thus extensively connected. Along the gaps between
the spiral coils, the intermediate layer thus has gaps which are
formed approximately up to half the layer thickness. Said layers
are each manufactured together with the spiral coils, or the gaps
can be produced from a flat intermediate layer by retrospective
partial abrasion in the region of the gaps of the external and
internal spiral coils. Said partial abrasion can take place, for
example, to half the layer thickness, or a rounded groove (score)
can be worked out of the intermediate layer.
[0027] A further embodiment is possible with the use of relatively
soft materials, such as, for example, polyurethane or rubber. In
this case, the intermediate layer is designed as a filled volume
(without grooves). The required deformations (predominantly shear
deformations for decoupling the layers) take place here by the
deformation capability of the soft material. An advantageous
variant thereof is an arrangement in which the material of the
intermediate layer is prevented from being squeezed out through the
spiral coil compensating gaps. By this means, the deformation of
the intermediate layer material is limited and the pressure between
the external spiral coils and internal spiral coils is partially
converted into a (hydrostatic) pressure on all sides which is
permissible to a relatively high degree even in the case of soft
materials. FIGS. 6a to 6c illustrate this geometrical variant of
the intermediate layer (2c). The continuous layer (2c2) is adjacent
here to the filling of the compensating gaps of the external spiral
coils (2c1) and the filling of the compensating gaps of the
internal spiral coils (2c3). The fillings of the compensating gaps
(2c1 and 2c3) can be realized here from the same material as the
surface of the intermediate layer (2c2) or from a different
material. A significantly softer material is advantageous here.
FIGS. 7a to 7c illustrate this variant of the intermediate layer
(with the elements 2c1, 2c2, 2c3) for illustrative purposes in
combination with the associated spiral coils (1) and (3).
[0028] A further embodiment is a structuring of the intermediate
layer for an improved extension behavior.
[0029] As illustrated in FIG. 11, the surface of the intermediate
layer upon contact thereof with a spiral coil can have scores or
lamellae which lie transversely with respect to the fiber direction
or longitudinal extent of the spiral coil. An extension of the
respective spiral coil is thus converted into an angular change or
tilting of the scores or lamellae, as a result of which the
decoupling properties are improved. Over and beyond the illustrated
arrangement, this can take place in each case on both sides of the
intermediate layer (wherein the scores or lamellae of the two sides
are at an angle to one another at which the spiral coils of the two
layers to be decoupled are also at with respect to one
another).
[0030] According to the invention, in general various variant
embodiments are also provided for the compensating gaps between the
spiral coils. The gaps can be filled either with an elastic
material (such as, for example, polyurethane, silicone, rubber, a
foam or an epoxy resin), thus promoting the above-described effect
of the hydrostatic pressure. Or the gaps can be left without a
filling (as a result of which they contain the ambient medium, such
as, for example, air), and therefore their deformation capability
is unlimited. Intermediate variants, such as a partial filling
(2d), are also possible, see FIGS. 8a to 8c. According to the
invention, variants are likewise provided in which yielding of the
material is promoted by targeted holes or air pockets (for example
by means of a compressible foam), and the deformation properties in
this region are positively influenced.
[0031] For the profile of the spiral coils, or the cross-sectional
geometry thereof, there are various embodiment options. In addition
to rectangular spiral coils, use can be made of round spiral coils
(cylinders), semi-cylindrical, oval (see FIGS. 8a to 8c) or else
substantially rectangular shapes with individual rounded sides. In
particular, a rectangular profile with a rounded side surface that
is in contact with the intermediate layer is considered
advantageous within the context of the invention since the shear
deformations occurring in the intermediate layer are thereby
reduced.
[0032] As an advantageous variant embodiment of the spiral coils
themselves, the surface of the latter, in particular of the
compression-loaded spiral coils, can at least partially contain
fibers which are tension-relieving with respect to an elastic
intermediate layer and have an orientation transversely with
respect to the longitudinal direction of the spiral coils. Said
fibers can carry a substantial portion of the transverse stresses
induced via the intermediate layer. As a result, the transverse
stresses or the transverse extensions in the load-bearing material
of the spiral coils (in the fibers in the longitudinal direction of
the spiral coils) turn out to be lower under loading, and therefore
the spiral coils can withstand higher loads in the longitudinal
direction of the spiral coils, in particular also cyclic loads.
[0033] For a final attachment of the spiral coils in a manner
appropriate to the load and deformation, the ends of said spiral
coils can have an increased layer thickness, the ends of the
component can have an increased tube diameter and/or there can be a
changed orientation of the spiral coils at the end of the
component. By this means, in the event of loading of the component
in said regions, a smaller longitudinal stress occurs in the spiral
coils, and therefore additional stresses from bending of the spiral
coils can be absorbed.
[0034] Similarly, additional end pieces can be attached to the ends
of the spiral coils (for example by means of adhesive connections),
the end pieces permitting a harmonious bending of the spiral coils
and a transfer of the forces in the longitudinal direction of the
spiral coils to an adjacent component, or an articulated attachment
of the spiral coils to a component end piece.
[0035] In a further advantageous variant embodiment, the bending
zone at the end of the spiral coils can be realized with a
narrowing of the spiral coils, as a result of which the deformation
capability in the event of a change in the pitch of the spiral
coils under loading is improved and the additional bending stresses
which occur turn out to be smaller than in the case of a spiral
coil of full width. In this case, the geometrical moment of inertia
relevant for the bending of the spiral coils in the circumferential
plane is reduced.
[0036] In addition to the illustrated structure having in each case
two layers of opposed spiral coils, constructions having three or
more layers of different spiral coil orientations are also
provided. For example, for improving the flexural rigidity of the
overall component, in addition to the two described
torsion-carrying layers of spiral coils of approximately +/-45
degrees, a third layer can be contained with fibers in the
longitudinal direction of the tube and optionally also with spiral
coils and gaps in the longitudinal direction of the tube. These can
likewise be decoupled from the adjacent layers by means of an
elastic intermediate layer in order to reduce the effects of
transverse extensions in the radial direction.
[0037] In an advantageous variant embodiment, the interior of the
tube constructed from spiral coils can contain a tube or a core of
flat material or solid material, in particular with fibers in the
longitudinal direction of the tube or fibers at approximately a
winding direction of 45 degrees with respect to the longitudinal
direction of the tube. The core leads here to an increased
load-bearing capability and/or rigidity against transverse force,
bending torques or radial loads. At the same time, it has a
sufficient deformation capability in the torsion direction because
of its small outside diameter (in relation to the overall
component). In order to locally increase the load-bearing
capability of the component against bending torques to a particular
degree, the described core can furthermore be expanded conically
locally (in particular at the ends of the component). In an
advantageous embodiment, the core is decoupled from the radially
outer layers of spiral coils by means of an elastic intermediate
layer.
[0038] In respect of the outer form, the described torsion carrier
(also referred to as "the component") can be designed in the form
of a tube or as a rectilinear or bent round bar. In an advantageous
embodiment, the component inside diameter and/or outside diameter
can be expanded in a funnel-shaped manner in the region of the ends
of the tube or bar. Said expansion can lead into a flat or conical
flange or into a coupling piece for connection to adjacent
components. When the diameter is expanded, the spiral coils at the
ends of the component can emerge radially into said flat or conical
flange. In an advantageous embodiment, the forces can be introduced
here into the spiral coils by means of an integrally bonded
connection, frictional connection or form-fitting connection.
[0039] In a further advantageous variant embodiment, the torsion
carrier in the form of a tube or bar can have a bent shape. It can
have, for example, the outer form of a screw or of a helical
spring. The tube or the bar can be curved here about one or more
axes. Similarly, in addition to a curvature, it can be twisted
about the tube longitudinal axis.
[0040] At its ends, the helical component can have a reduced screw
diameter and/or a changed screw thread height.
[0041] In the form of a helical spring which can be loaded in
tension or compression, the bent tube or the bent bar is
predominantly subjected to torsion section loads. In this case, the
structure described according to the invention having opposed
spiral coils which are decoupled from one another has been shown to
be particularly capable of bearing loads. The predominantly
uniaxial state of stress in the composite fiber spiral coils
permits a higher utilization of the composite fiber material with
significantly higher permissible stress and extension values. The
torsion carrier (in the form of a helical spring) thus withstands
greater loads and amplitudes. Or, conversely, with a predetermined
level of load and movement amplitude, said torsion carrier can be
realized with a significantly lower use of material. This applies
particularly for cyclic loading forms.
[0042] On the basis of the described torsion carrier structure,
different devices having different application-specific
constructional forms can be realized. These include in particular a
torsion tube spring, a torsion bar, a helical spring, a drive
shaft, a flexurally elastic torsion shaft or a compensating shaft
(or elastic coupling) with angular and offset tolerances.
[0043] With regard to claim 3, it is noted that the latter
describes an arrangement in multiple form, wherein a plurality of
spiral coils are in each case distributed over the circumference
and preferably run parallel to one another in an axial direction of
the torsion carrier. A multiple form of at least 3 is preferably
provided, furthermore preferably a multiple form of at least 6, and
therefore a layer contains at least three spiral coils, furthermore
preferably at least six spiral coils. For most technical
applications, an arrangement of in each case more than 10 spiral
coils distributed over the circumference has proven
advantageous.
[0044] The ratio between the height of the spiral coils (as viewed
in the radial direction) and the width of the spiral coils is
preferably between 1:1 and 1:3.
[0045] As examples of damping materials as per claim 5, reference
is made in particular to rubber or polyurethane and other materials
having similar elastic properties and damping properties.
[0046] Of the layers mentioned in claim 10, in particular 2, 3, 4,
5, 6, 7 or 8 layers are provided.
[0047] At least one of the layers mentioned in claim 11 preferably
contains spiral coils and gaps in the component longitudinal
direction, leading to an increased flexural rigidity or flexural
load-bearing capability.
[0048] The core discussed in claim 12 is formed in particular from
a solid cylindrical element (solid bar) and/or from a hollow
cylindrical tube, wherein both can be constructed in particular
from composite fiber materials. Alternatively or in addition
thereto, the core preferably has fibers with an orientation in the
tube longitudinal direction and/or fibers with a 45 degree
orientation (optionally with a tolerance of +/-15 degrees).
[0049] Cylindrical in claim 13 means in particular that the torsion
carrier is designed in the form of a tube or of a rectilinear round
bar.
[0050] With regard to a diameter changing, according to claim 13,
in the direction of the component ends, in an advantageous
embodiment an inside diameter expanding outwards in the form of a
funnel can be formed. For example, the component ends can thus lead
into a flat or conically formed flange or in a coupling contour for
connection to adjacent components. Adjacent components mean in
particular components which are intended to be coupled to the
torsion carrier for rotation therewith. The inside diameter is
preferably predetermined here by the internal contour of an
internal spiral coil and/or by an internal layer adjoining the
inner side.
Definitions and Explanations
[0051] Spiral coil The spiral coil, also called helix, screw,
helical curve, cylindrical spiral, is a curve which winds with a
constant pitch around the casing of a cylinder. It arises from a
surface (=layer, plane) which is curved on a radius and has helical
slots. [0052] Layer Tubular layer of the component (on a
cylindrical circumferential surface) with a defined function. This
can either be an intermediate layer or a layer with what are
referred to as load-bearing spiral coils (external or internal
spiral coils for transferring tensile and compressive stresses).
[0053] Form Design of a layer as a spiral coil with gaps. [0054]
Intermediate layer Layer for decoupling extensions between two
adjacent load-bearing layers (decoupling layer between
tension-transferring external spiral coils and
compression-transferring internal spiral coils). [0055] Hollow
cylinder Hollow circular cylinder. [0056] Compensating gap Gap
between the spiral coils of a layer, the gap permitting in
particular extension between the spiral coils. In this context, the
terminology of a "slotted" arrangement can also be used, wherein
spiral coils and compensating gaps arise from a closed layer. The
compensating gaps can be filled or unfilled. [0057] Transverse
extension Extension transversely with respect to the fiber
direction, the extension because of the shortened extension
distance of the matrix having significant effects on the
load-bearing capability of composite fiber materials, in particular
under repeated loadings (fatigue). [0058] Directions The main
direction of extent of the spiral coils should be understood as
meaning in particular the spiral coil longitudinal direction, i.e.
the direction of the greatest longitudinal extent of a spiral coil
that preferably extends on a helical curve around an (optionally
only virtual) cylinder circumferential surface. [0059] The spiral
coil width is understood as meaning the direction which is located
in the casing plane and is orthogonal to the main direction of
extent. [0060] The extent in the third dimension of the spiral
coils is referred to as the height or thickness of the spiral
coils. In the case of a tube or bar, this corresponds to the extent
in the radial direction.
Supplementary References to the Figures
[0061] Drawings 2 to 8 illustrate the layers of the component in
the unwound state for reasons of better clarity.
[0062] The features of the invention that are disclosed in the
present description, in the drawings and in the claims may be
essential both individually and in any desired combinations for
realizing the invention in its various embodiments. The invention
is not restricted to the embodiments described. It can be varied
within the scope of the claims and taking into consideration the
knowledge of a relevant person skilled in the art.
LIST OF REFERENCE SIGNS
[0063] 1 External spiral coil [0064] 2 Intermediate layer [0065] 3
Internal spiral coil [0066] 4 Compensating gap between external
spiral coils [0067] 5 Compensating gap between internal spiral
coils [0068] 2a Intermediate layer in the region of intersection of
spiral coils of adjacent layers [0069] 2b1 Part of the intermediate
layer with contact with the external spiral coils [0070] 2b2 Part
of the intermediate layer with contact with the internal spiral
coils [0071] 2c1 Filling of the compensating gap of the external
spiral coils [0072] 2c2 Flat intermediate layer [0073] 2c3 Filling
of the compensating gap of the internal spiral coils [0074] 2d
Intermediate layer between oval spiral coils, the intermediate
layer not projecting or projecting partially or completely into the
gaps between the spiral coils [0075] 11 Structured intermediate
layer for improving the deformation capability
* * * * *